Chief executives of large retailers including Bunnings are set to be grilled about their treatment of customers and suppliers by a new parliamentary inquiry that is causing unease within the Coalition for being too populist, underscoring how big business is being pulled into the politics of the cost-of-living debate.

Months after a sometimes fiery inquiry into supermarket giants Coles and Woolworths wrapped up, the Senate’s economics committee has called a new probe into big-box retail chains selling household items outside the reach of the food and grocery sector’s code of conduct.